title: Study of the magnets used for a mobile isocenter carbon ion gantry.
abstract: A conceptual design of a mobile isocenter carbon ion gantry was carried out in the framework of the Particle Training Network for European Radiotherapy (PARTNER) and Union of Light Ion Centres in Europe (ULICE) projects. To validate the magnets used in this gantry, Finite Element Method (FEM) simulations were performed with COMSOL multiphysics; the purpose was to evaluate the magnetic field quality and the influence of additional support structures for correctors, 90° bending dipole and quadrupoles, both in dynamic and static regimes. Due to the low ramp rates, the dynamic effects do not disturb the homogeneity and the magnetic field level. The differences between the stationary field and the corresponding dynamic field after the end of the ramps are in the order of 10(-4); it implies that the magnets can be operated without significant field lag at the nominal ramp rate. However, even in static regime the magnetic length of corrector magnet decreases by 5% when the rotator mechanical structure is considered. The simulations suggest an optimization phase of the correctors in the rotator.
authors.affiliation: Centro Nazionale di Adroterapia Oncologica (CNAO), Strada Privata Campeggi, 53, Pavia, Italy. jhonnatan.moreno@cnao.it
authors.forename: Jhonnatan Osorio
authors.initials: JO
authors.lastname: Moreno
authors.forename: Marco G
authors.initials: MG
authors.lastname: Pullia
authors.forename: Cristiana
authors.initials: C
authors.lastname: Priano
authors.forename: Valeria
authors.initials: V
authors.lastname: Lante
authors.forename: Monica M
authors.initials: MM
authors.lastname: Necchi
authors.forename: Simone
authors.initials: S
authors.lastname: Savazzi
mesh_terms: D000465:Algorithms; D002244:Carbon / Q000737:chemistry; D003198:Computer Simulation; D004867:Equipment Design; D020342:Finite Element Analysis; D063193:Heavy Ion Radiotherapy / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008280:Magnetics; D059346:Magnets; D009369:Neoplasms / Q000532:radiotherapy*; D010315:Particle Accelerators; D012984:Software
chemical_list: D002244:Carbon
keywords: carbon ion gantry; field homogeneity; magnet design; magnetic length